1. Field of the Invention
In traveling wave tubes, an electron gun is generally disposed at one end of the tube and a collector at the other end. Collectors are necessary in collecting a beam of electrons which emanates from the electron gun. For insulated collectors, the collector generally comprises a tubular wall, a tubular insulating wall, a cylindrical electrode positioned within the insulating wall, and a buffer interposed between the electrode and the insulating wall. A novel buffer is the subject of the present invention.
2. Description of the Prior Art
In general, the collector electrode is bonded directly to the insulating wall. The bonding ensures the proper alignment of the electrode and facilitates the efficacious dissipation of heat from the electrode to the exterior of the collector wall. When the electrode undergoes extreme operational temperatures, its expansion and contraction invariably causes the insulating wall-to-electrode bonds to sever. One remedy for this problem is to machine helical slots on the external surface of the electrode in order to permit the expansion and contraction of the electrode. Frequently, the slots extend to the internal surface of the electrode. Another remedy is to use buffers between the electrode and the insulating wall. For example, rings are disclosed in U.S. Pat. No. 3,626,230, by Stewart and U.S. Pat. No. 3,317,787, by Doyle.
However, the prior art devices are deficient. One deficiency is that the machining of helical slots on the electrode is extremely time consuming and expensive. Another deficiency is that the assembly and manufacturing of rings are equally time consuming and expensive.